Public address apparatus



April 21 1964 N. J. STOWELL 3,129,782

PUBLIC ADDRESS APPARATUS Filed May 4. 1961 2 Sheets-Sheet 1 l4 I3 I I5 III 23 f g-I- l5 I2 I INVENTOR I BY ATTORNEY April 21, 1964 N. J. STOWELL 3,129,782

PUBLIC ADDRESS APPARATUS Filed May 4, 1961 2 Sheets-Sheet 2 III!IIIIIIIIIIIIIIIIlIIII/I I 1 I llaf/zan 34 44 36 ATTORNEY United .States Patent 3,129,782 PUEIJEC ADDRESS APPARATUS Nathan 5. Stowell, Jackson, Miss, assignor to James Willis Hughes, Jackson, Miss. Filed May 4, 1961, Ser. No. 107,784 2 Claims. (\Cl. 181-31) This invention relates to new and useful improvements in public address apparatus, and in particular the invention concerns itself with the housing and mounting of loudspeakers.

As such, the invention represents certain improvements in the apparatus disclosed in my co-pending patent application Serial No. 65,084 filed October 26, 1960, of which this application is a continuationin-part.

My aforementioned co-pending application discloses a lectern, pulpit, speakers stand, or the like, in the form of a cabinet provided with loudspeaker accommodating compartments, each equipped with a speaker mount or support which separates the compartment into a sound transmitting chamber and a static air chamber, the latter being airtight and loaded with static air so as toact upon the energizing mechanism of the speaker and restrict distortion compliance of the sound emitting mechanism of the speaker, whereby to control compliance or excursion of the sound emitting mechanism to produce only the applied electro-motive force without undersirable results of phase distortion.

The principal object of the present invention is to structurally and functionally improve the arrangement of the speaker compartment and speaker mount, whereby the same are better adapted to fulfill their intended function with ease, convenience and economy of fabrication and assembly.

With the foregoing more important object and features in view and such other objects and features as may become apparent as this specification proceeds, the invention will be understood from the following description taken in conjunction with the accompanying drawings, wherein like characters of reference are used to designate like parts, and wherein:

FIGURE 1 is a view partly in plan and partly in horizontal section, showing one embodiment of the loudspeaker compartment and mount;

FIGURE 2 is a view, partly in side elevation and partly in vertical section, of the same;

FlGURE 3 is a front elevational View thereof;

FIGURE 4 is a view, partly in plan and partly in horizontal section, showing a speaker mount of different proportions;

FIGURE 5 is a front elevational view of the speaker mount shown in FIGURE 4;

FIGURE 6 is a view, partly in side elevation and partly in vertical section, of another embodiment of the speaker compartment and mount, this embodiment accommodating a pair of speakers for stereophonic purposes and also including a supporting base;

FIGURE 7 is a front elevational view of the speaker compartment and mount structure of FIGURE 6, showing the supporting base partly in elevation and partly in vertical section; and

FIGURE 8 is a view, partly in plan and partly in horizontal section, of the device shown in FIGURES 6 and 7.

Referring now to the accompanying drawings in detail, more particularly to FIGURES l-3, the loudspeaker housing and mount is designated generally by the reference numeral 10 and embodies in its construction a boxshaped housing proper 11 having an open front and including a pair of side walls 12, a top wall 13, a bottom wall 14- and a back wall :15, these walls being preferably formed from wood, or the like, and secured together at their contiguous marginal edges in any suitable manner.

3,129,782 Patented Apr. 21, 1964 The housing 11 defines a compartment for accommodating a speaker mount 16 which is of a hollow, frusto-pyramidal configuration and includes a set of four inwardly convergent wall panels 17 secured at their convergent ends or edges .to a support plate 18 formed with a circular opening 119 in which a conventional loudspeaker (not shown) may be mounted. The divergent ends or edges of the wall panels 17 have secured thereto a laterally projecting marginal frame or spacer 20 which fits snugly into the open front of the housing 11 and is suitably secured therein so that the mount 16 is disposed in the housing in a re-entrant manner, as shown.

The mount 16 separates the interior of the housing 11 into a front portion or a sound transmitting chamber 21 and a rear portion or a static air chamber 22, the latter being airtight and loaded with static air so as to act upon the energizing mechanism of the loudspeaker (not shown) in the opening 319 and restrict distortion compliance of the sound emitting mechanism and thereby control compliance of the latter to produce only the applied electro-motive force without undesirable results of phase distortion, it being noted that the sound waves emitted by the speaker are concentrated into a forwardly divergent beam, as indicated by the arrows 23, the vertical and horizontal dimensions of which are controlled by the angular relationship of the mutually divergent wall panels .17.

The static air chamber 22 and the re-entrant loud speaker mount 16- defining sound transmitting chamber 21 provide symmetrical front and back loading for a loudspeaker (not shown) mounted on the speaker support plate 18, whereby faithful loudspeaker compliance is achieved.

The non-parallel angular relationship of the walls of the re-entrant mount 16 with respect to the walls of the housing 11 create anechoic properties within the static air chamber 22 thereby reducing cabinet resonance within the static air chamber.

The arrangement of the speaker mount 16a shown in FIGURES 4 and 5 is substantially the same as that of the mount 16, the mount 16a including convergent wall panels 17a secured at their convergent edges to the support plate that and at their divergent edges to a laterally projecting marginal frame Z'Ila. However, in the mount la, the sound transmitting chamber 21a is somewhat longer or deeper than the chamber 16, whereby to effect a greater horizontal and vertical concentration of sound waves emitted therefrom.

The modified embodiment of the invention shown in FIGURES 6'8 is adapted to accommodate a pair of stereophonic speakers and, as designated generally by the reference numeral 30, this embodiment comprises a vertically elongated housing 31 having an open front and including a pair of side walls 32, a top wall 33, a bottom wall 34 and a back wall 35. The speaker mount 36 includes pairs of inwardly convergent wall panels 37, 38, secured at their convergent edges to a vertically elongated support plate d9, the latter being formed with a pair of vertically spaced, circular openings 40 to accommodate the two speakers (not shown). The divergent edges of the wall panels 37, 38 have secured thereto a laterally projecting spacer frame 4 1 which fits snugly into and is suitably secured in the open front of the housing 31.

The speaker mount 36 also includes a pair of spaced, angulated wall panels 42 which extend from the intermediate portion of the plate 39 to the open front of the housing 31, it being observed that the panels 42 include inner portions 42a which are mutually divergent in a vertical plane and substantially parallel to the wall panels 38, while the outer portions 42b of the panels 42 are parallel and horizontal. The inner edges of the panel portions 42a terminate at the adjacent edges of the openings 40 in the plate 39, the entire mount 36 thus providing therewithin a pair of sound transmitting chambers 43 for the respective speakers in the openings 46, the chambers 43 being separate from the airtight static air chamber 44 in the housing 31. The portion of the mount 36 between the panels 42 defines a compartment 45 for accommodating a suitable amplifier unit (not shown).

The entire device 3%} may be used horizontally, that is, while resting on either one of its walls 32, although it is preferred that it be used vertically, as illustrated, in which instance a separate supporting base 4-6 may be provided therefor. The base 46 comprises a perimetric frame 47 provided at the inside thereof with a perimetric bead 48 which is spaced downwardly from the upper edge of the frame so that the bottom end portion of the device 30 may be received Within the frame 47 and rested on the bead 48. The bead 48 is reinforced by suitable gussets 49 and a bottom plate 56 may be provided on the frame, it so desired.

While in the foregoing there have been described and shown the preferred embodiments of the invention, various modifications may become apparent to those skilled in the art to which the invention relates. Accordingly, it is not desired to limit the invention to this disclosure and various modifications and equivalents may be resorted to, falling within the spirit and scope of the invention as claimed.

What is claimed as new is:

l. A housing and mount for loudspeakers, comprising a box-shaped housing proper having an open front and being otherwise closed, and a re-entrant mount proper provided in said housing proper, said mount proper including a set of mutually convergent wall panels extending inwardly from the borders of the open front and joined thereto, a speaker support plate secured to the convergent edges of said wall panels, and a pair of spaced partition panels extending between said wall panels and coacting therewith and with said support plate to provide a pair of spaced sound transmitting chambers in said mount proper, said sound transmitting chambers having an open front at the open front of said housing proper, a pair of apertures in said support plate each opening into a respective one of said sound transmitting chambers and loudspeakers mounted in said apertures and facing said open front, and the interior of the housing proper rearwarding and at the sides of said mount proper defining a substantially anechoic static air chamber, said sound transmitting chambers and said static air chamber providing symmetrical front and rear loading for said speakers.

2. The device as defined in claim 1 wherein a portion of said mount proper between said partition panels defines an amplifier receiving compartment.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Mar. 6, 

1. A HOUSING AND MOUNT FOR LOUDSPEAKERS, COMPRISING A BOX-SHAPED HOUSING PROPER HAVING AN OPEN FRONT AND BEING OTHERWISE CLOSED, AND A RE-ENTRANT MOUNT PROPER PROVIDED IN SAID HOUSING PROPER, SAID MOUNT PROPER INCLUDING A SET OF MUTUALLY CONVERGENT WALL PANELS EXTENDING INWARDLY FROM THE BORDERS OF THE OPEN FRONT AND JOINED THERETO, A SPEAKER SUPPORT PLATE SECURED TO THE CONVERGENT EDGES OF SAID WALL PANELS, AND A PAIR OF SPACED PARTITION PANELS EXTENDING BETWEEN SAID WALL PANELS AND COACTING THEREWITH AND WITH SAID SUPPORT PLATE TO PROVIDE A PAIR OF SPACED SOUND TRANSMITTING CHAMBERS IN SAID MOUNT PROPER, SAID SOUND TRANSMITTING CHAMBERS HAVING 